Related Experiment Video
Updated: Jan 29, 2026

Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells
Published on: March 19, 2017
Valence Variations by B-Site Doping in A-Site Columnar-Ordered Quadruple Perovskites Sm2MnMn(Mn4- xTi x)O12 with 1 ≤
Alexei A Belik1, Lei Zhang1,2, Ran Liu1,2
1Research Center for Functional Materials , National Institute for Materials Science (NIMS) , Namiki 1-1 , Tsukuba , Ibaraki 305-0044 , Japan.
Abstract:
Sm2MnMn(Mn4- xTi x)O12 with 1 ≤ x ≤ 3 were prepared by a high-pressure, high-temperature method at 6 GPa and about 1570-1670 K. They belong to a family of A-site columnar-ordered quadruple perovskites A2A'A″B4O12, where A' is a site with a square-planar coordination and A″ is a site with a tetrahedral coordination. Their crystal structures were investigated using synchrotron X-ray and neutron powder diffraction. They crystallize in space group P42/ nmc (No. 137) with a = 7.41172 Å and c = 7.97131 Å for x = 1, a = 7.54945 Å and c = 7.76756 Å for x = 2, and a = 7.63949 Å and c = 7.70339 Å for x = 3 at 295 K. The determined charge and cation distributions are [Sm3+1.88Mn2+0.12]A[Mn3+]A'[Mn2+0.88Sm3+0.12]A″[Mn3+3Ti4+]BO12 for x = 1, [Sm3+1.91Mn2+0.09]A[Mn2+]A'[Mn2+0.91Sm3+0.09]A″[Mn3+2Ti4+2]BO12 for x = 2, and [Sm3+1.88Mn2+0.12]A[Mn2+0.88Sm3+0.12]A'[Mn2+]A″[Mn2+Ti4+3]BO12 for x = 3. Mn and Ti are distributed randomly in one B site in all compounds with the average oxidation state changing from +3.25 to +3.5 per one B atom, and such flexibility is realized because Mn at the A' site can change its oxidation state between +2 and +3. Sm and Mn are slightly disordered between the A and A″ sites for x = 1 and 2, and between the A and A' sites for x = 3. The x = 1 sample shows spin-canted antiferromagnetic properties with TN = 27 K, and the x = 2 sample, with TN = 62 K. On the other hand, the x = 3 sample is a ferrimagnet, confirmed by neutron diffraction, with TC = 40 K. The x = 3 sample shows relaxor-like dielectric properties below 220 K.
Related Concept Videos
Valence Bond Theory
Valence Bond Theory
What is Variation?
The range, standard deviation, standard error, and variance are the different measures of variation.
Range: The range is the difference between its maximum and...
Conservative Site-specific Recombination and Phase Variation
The recognition sites for Cre recombinase called LoxP...
Variation
When independent and dependent variables are plotted on a scatter plot, the slope of a line is a value that describes the rate of change between the two...
Valence Bond Theory and Hybridized Orbitals
A σ bond (single bond in a Lewis structure) is a covalent bond in which the electron density is...

